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 A227499 Number of the Lipschitz quaternions in a reduced system modulo n. 15
 1, 8, 48, 128, 480, 384, 2016, 2048, 3888, 3840, 13200, 6144, 26208, 16128, 23040, 32768, 78336, 31104, 123120, 61440, 96768, 105600, 267168, 98304, 300000, 209664, 314928, 258048, 682080, 184320, 892800, 524288, 633600, 626688, 967680, 497664, 1822176 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA Multiplicative: a(2^s) = 2^(4s-1); a(3^s) = 16*3^(4s-3); a(5^s) = 32*3*5^(4s-3). MATHEMATICA cuater[n_] := Flatten[Table[{a, b, c, d}, {a, n}, {b, n}, {c, n}, {d, n}], 3]; a[n_] := Length@Select[cuater[n], GCD[#.#, n] == 1 &]; Array[a, 20] CROSSREFS Cf. A079458, A060968, A087784. Sequence in context: A067239 A152750 A121355 * A168012 A222816 A280056 Adjacent sequences:  A227496 A227497 A227498 * A227500 A227501 A227502 KEYWORD nonn,mult AUTHOR José María Grau Ribas, Jul 13 2013 STATUS approved

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Last modified May 7 19:23 EDT 2021. Contains 343652 sequences. (Running on oeis4.)